22 mins: Torreira wins another free-kick, and has made himself very unpopular with the home fans. I still think the decision to send Deeney off was the right one. “Interesting foul from Troy Deeney,” says Gary Naylor. “I suspect (and I think Deeney has said as much in the past) that he was testing the waters with an early ‘orange’ fully expecting that a yellow would come. It didn’t, and rightly so. Falls into the ‘too clever by half’ drawer.”

17 mins: It has been a mind-boggling implosion from Watford, who had started the game so well but have gifted their opponents a goal and a man advantage. Bizarre decision-making from two very experienced players.

14 mins: Hughes tackles Mkhitaryan, who collapses to the floor and rolls around clutching his ankle. The referee tells him to get up, and so he stops rolling around, gets up and trots off, completely fine.

Troy Deeney gets sent off!

11 mins: The referee, or his assistant, has seen something the cameras have not. There was apparently a coming together with Torreira. Arsenal claim there was an elbow, and the referee brings out a red card!

Javi Gracia has a pre-match chat. He says his team will start with a back three, which is a significant departure for him:

With the players we have we can change shape during the game. It depends on different circumstances. [Emery] came to see us many times but I think it’s not the most important to know each other. The most important is what is happening on the pitch and at this moment the main protagonists are the players. I think we’ll see a good game and I hope we’ll have a good result at the end for us.

I think the absence of both Pereyra and Deulofeu is very significant for Watford. The Argentinian has been in mediocre form for much of the season, but either of those players can conjure a goal at any moment, and without them their attack is rather prosaic.

Arsenal made six changes for their Premier League clash at Watford as Konstantinos Mavropanos made his first start since May.

The Gunners face Napoli in the second leg of their Europa League quarter-final and travel to Italy defending a 2-0 lead.

Unai Emery is likely to have one eye on that fixture with Mavropanos starting as well as fellow recalled players Shkodran Mustafi, Henrikh Mkhitaryan, Alex Iwobi and Bernd Leno, while Granit Xhaka recovered from a groin problem to be included.

Watford meanwhile made four alterations from their victorious FA Cup semi-final win over Wolves as Ben Foster, Christian Kabasele, Daryl Janmaat and Adam Masina came in.

Good stat from Bill Edgar in the Times this morning: if Watford do not beat Arsenal tonight it will ensure that this will be the first top-flight case of three seasons in a row with the same teams filling the top six places (in any order).

Hello world!

Watford won this fixture last year, a riproaring 2-1 victory sealed by Tom Cleverley’s stoppage-time strike which prompted Troy Deeney, scorer of his side’s other goal that night, to deliver his sermon about Arsenal and their issue with “cojones”. So the Gunners will be wanting to make amends for that.

Arsenal won their home game against Watford in September, two goals in three late minutes bringing them a 2-0 victory. They only had two shots on target that day (Watford had five) and most observers declared that the visitors should have won it. So the Hornets will be wanting to make amends for that.

Then there’s the matter of Arsenal’s away form this season. They have the division’s third-best home record, accumulating three points less than Liverpool have at Anfield and four points less than Manchester City have at the Etihad. There are nine teams that have won more points away from home (though Arsenal have played two fewer away matches than most top-flight teams) and of the Gunners’ five away wins three came against teams in the relegation zone. The highest-placed team they have beaten away from home this season is Bournemouth, in 12th. So they will want to make amends for that.

Factor in the fact that the managers are former teammates, having spent a year together at Real Sociedad, and paid-up members of a mutual appreciation society. “He’s a good friend and it’s good to see him again, we are very close,” says Javi Gracia. “We sometimes talk away from football and spend time together. We had dinner, their coaches and with our coaches,” says Unai Emery. “They are my friends, not only Javi Gracia but also his assistant Zigor Aranalde and Iñigo Arteaga.”

Plus Watford want to finish seventh, and to be in full form for next month’s FA Cup final, while Arsenal want to finish in the top four. Thus, and to summarise, there’s plenty riding on this. Should be a good ’un.